The invention relates to deposition techniques involving thermal evaporation. In general, such techniques are used, for example, in the production of thin-film solar cells which requires large-area deposition techniques. Known techniques include roll coating by thermal evaporation in which a semiconductor film is deposited on a wide flexible substrate continuously drawn over an array of thermal evaporation sources. These sources require a significant quantity of heat shielding. The only elements of the source not covered by such heat shielding are the effusion nozzles wherein the nozzle tip extends beyond the outermost surface of the heat shielding.
U.S. Pat. No. 4,325,986 discloses work by others in this field.